Posting Canadian Property on Craigslist?

I like your site and have searched the questions asked, but did not find what I am looking for. My question is in reference to the code I must place in the zip box address for my property. I have tried putting in my postal code, but that is rejected. I have asked the question of Craigslist, but always get their pre-packaged response. I know one can post, but not without the magic code for Canadian properties. I appreciate your time and expertise.